Interpretive Summary: Ratoon stunt of sugarcane has been reported to cause yield losses; however, the major sugarcane cultivars in currently grown in Florida have not been evaluated. Recent, yield trials indicate that losses occur in the currently grown Florida cultivars and that other available control practices should also be used to restrict losses. There is cultivar variability in reaction to ratoon stunt.

Technical Abstract:
The yield response of recently released CP-cultivars to ratoon stunt has not been determined. Cane and sugar yields of Liefsonia xyli subsp. xyli (Lxx)-infected and healthy sugarcane plants of cultivars that are currently major commercial cultivars that have not been in prior tests as well as former cultivars that have been included in previous tests were compared in three field experiments. Yield trials were established by planting either inoculated or Lxx-infected stalks and stalks from healthy plants for comparison in the plant and first ratoon crops. Plants infected with Lxx had reduced sugar and cane yields compared with healthy plants. Although the yield losses were not always significant, the trends were consistent among all three trials. The results indicate that ratoon stunt can cause cane and sugar losses in commercial cultivars currently grown in the Florida sugarcane industry, and control practices should be used. Although CP 72-2086 is considered resistant to spread and had fewer plants infected after inoculation than other cultivars, infected plants had significant losses in one trial.